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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

The paleoethnobotanical record of central Ohio - 100 B.C. to A.D. 800 : subsistence continuity amid cultural change /

Wymer, Dee Anne, January 1987 (has links)
Thesis (Ph. D.)--Ohio State University, 1987. / Includes bibliographical references (leaves 327-346). Available online via OhioLINK's ETD Center
52

The paleoecology of coastal sandplain grasslands on Martha's Vineyard, Massachusetts

Stevens, Andrea 01 January 1996 (has links)
The vegetation history of the island of Martha's Vineyard, Massachusetts during the last millennium was investigated with particular focus on the occurrence and distribution of coastal sandplain grasslands prior to European settlement. The objectives of the research were (1) to examine by paleoecological methods the possibility that grasslands existed on Martha's Vineyard as a "natural" vegetation type before the introduction of European agriculture, (2) to address the effects of land use, fire, soils, and near-coastal location on the occurrence of grasslands across the island during the last 1000 years, and (3) to provide a historical perspective to grassland dynamics that may be relevant to conservation planning and management. To address these research objectives, 12 sediment cores were collected from Martha's Vineyard and analyzed for pollen and charcoal. Nine cores were recovered from the outwash plain, where coastal sandplain grasslands occur today or are known to have occurred historically, and 3 cores were collected from the moraine of the island. Sediments from multiple cores were analyzed to characterize spatial and temporal vegetation changes across the island that may be related to land-use history, fire occurrence, or soil conditions. Vegetation near study sites was sampled to characterize modern grassland and forested communities and to identify environmental gradients responsible for variations in species abundances. Modern vegetation types were also compared to surface pollen assemblages and analogous prehistoric pollen spectra. Results suggest that sandplain grasslands or associated vegetation types occurred on Martha's Vineyard prior to European settlement, at least in localized areas near coastal ponds on the outwash plain, and that these grassland types probably occurred in response to burning by native American Indians. The importance of prehistoric fire on the island is inferred from higher pre- than post-settlement charcoal content in sediments from most study sites. The near-coastal influences along the island's southern shoreline, where early successional communities occur today, may also have favored grassland vegetation types in the past.
53

Vascular cambium and wood development in selected carboniferous plants /

Cichan, Michael Anthony January 1984 (has links)
No description available.
54

Grassland to desert : Holocene vegetation and climate change in the northern Chihuahuan Desert /

Hoyt, Cathryn A. January 2000 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 202-224). Available also in a digital version from Dissertation Abstracts.
55

Holocene fire and climate in rangeland ecosystems of Southwestern Idaho /

Nelson, Nathan Alfred. January 2009 (has links)
Thesis (M.S.)--Boise State University, 2009. / Includes abstract. Includes bibliographical references (leaves 81-91).
56

Holocene changes in fire, climate and vegetation in the northern Rocky Mountains of Idaho and western Montana /

Brunelle-Daines, Andrea, January 2002 (has links)
Thesis (Ph. D.)--University of Oregon, 2002. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 170-178). Also available for download via the World Wide Web; free to University of Oregon users.
57

Late Pleistocene biogeography of the western Missouri Ozarks

King, James E. (James Edward), 1940- January 1972 (has links)
No description available.
58

Late quaternary environments in the eastern Grand Canyon: vegetational gradients over the last 25,000 years

Cole, Kenneth Lee January 1981 (has links)
No description available.
59

Fossil angiosperms as indicators of early Tertiary conditions in Africa with special reference to the Miocene flora of Rusinga Island, Lake Victoria

Chesters, Kathleen Isabel Margaret January 1958 (has links)
No description available.
60

Palynological and paleoecological assessment of a Pennsylvanian shale overlying the Danville coal member (VII) in Sullivan County, Indiana

Madigosky, Stephen R. January 1987 (has links)
Shale samples from three Upper Pennsylvanian assemblages overlying the Danville (No. 7) Coal Member in Sullivan County, Indiana were compared with respect to miospore content. Eight samples from each of the Hawthorn, Dugger and Minnehaha mines were chemically macerated and analyzed for pollen/spore content. A total of 108 species assigned to 40 genera were recovered. A comparison of the palynoflora from the three assemblages reveals 17 genera and 32 species found in common. The palynoflora is dominated by the following four genera: Lycospora, Laevigatosporites. Punctatisporites and Punctatosporites. Genera of secondary importance include: Spinosporites, Crassispora, Calamospora, Latosporites, Cycloqranisporitesand Thymospora. These findings are similar to other palynofloras of comparable age from the United States and Europe.Abundance data at each site from the three localities were analyzed using cluster analysis. This was achieved employing the Baroni-Urboni-Buser correlation coefficient (complete linkage, furthest neighbor strategy). This method uses presence-absence data to indicate association between sites. Results revealed few taxonomic differences within or between mines. The uniformity in palynoflora observed between all sites is indicative of contemporaneous deposition which represents a regional flora. Percentage of miospore components assigned to previously established plant affinities were arranged by major plant groups. This allowed indirect comparison with megaflora from the same area as reported by Pheifer (1979). Results were found to be complementary and corroborative. Data from the three mines revealed an abundance of arborescent lycopods, ferns and sphenopsids with few gymnosperms. This is suggestive of current paleoenvironmental models which indicate a wet swamp regime.It is likely that the three areas in this study represent a small portion of a vast freshwater swamp located on the eastern periphery of the Illinois Coal Basin. This interpretation is substantiated by species composition, uniformity in palynoflora and absence of species associated with saline environments. / Department of Biology

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